Same here.
Started playing in February 2018. Playing pretty much every day since then.
I purchased plat frequently, mostly with 75% discounts, 45 times in total.
The last time I've seen a 75% was in September 2021.
This feels intentional, and a bit greedy, to be honest.
IF DE wants me to pay more for plat, their plan backfired: I'm not paying at all. I'd rather take my time to farm and trade.